Broken gearbox:(

4GTuner

Help Support 4GTuner:

nonickname

Well-Known Member
Joined
Jul 18, 2010
Messages
184
Location
Seaford, Melbourne
Hi guys,

Here is a long drawn out description of my launching failure :rolleyes:

Went for my first launch. I drop the clutch and the car doesn't move. Didn't even jolt forward or make any noise. The cars is stuck in first gear. I turned it off and yanked it out of first. With the clutch in I cant select first or second. Start the car up to get back home as i could stil select 3rd. I drive back doing about 40. No noise or anything unusual at this point apart from 1st and 2nd having no drive. I touch the gas a bit and as soon as it slightly came on boost. Bang! no more third gear and the box is now grinding away. I select 5th and limp it home. Still makes a noise now all the way back. The next morning Im having a look and notice oil on the bottom of the gearbox. Not alot but enough to make a few drops on the ground. I can now select first but it does nothing. Still cant even select second. Third goes in and works but as soon as clutch is let out and motions forward the grinding noise starts. 4th and 5th seem fine and reverse is gone.

Has anyone had this happen to them? In your opinion is this a full box rebuild? I know it has to come out either way. Iam just trying to work out how bad or not so bad this is so I have a rough idea of the cost.
 
sounds like more than a rebuild. sounds like gears and stuff too.
check here for idea of parts prices. dunno if yours is awd or fwd but jack lists parts for both.
http://www.jackstransmissions.com/pages/dsm-selection
 
remove box.....drop in bin. get another box...strip...inspect...repair as need needed....install.

why drop old one in bin? new parts will probably cost more than a known working non lsd box.
 
Yep as said above. Remove and toss I'd say.
Input shaft will be toast and more than likely you've also done damage to the intermediate shaft when 3rd gear decided to ingest the bits from 1st gear.
If you were really realy unlucky you also stufed the drive teeth on the centre diff as well.
It will probably look much worse than this inside!

Boom004.jpg
 
Haha thanks guys. Sounds like I might be getting in touch with one of my "cuzzy bros" back home in nz and find a rebuilt one over there. they are a dime a dozen and will be less than $1000 nz delivered so probably the cheapest way. Gota love cars! <_<
 
Sounds like you originally broke 1st/2nd shifter fork then the pieces ended up causing more damage the more your drove it.
Rule of thumb, if you break your gearbox immediately shut down and get it towed - its cheaper. DO NOT keep driving it unless you're prepeared to buy another gearbox. Once you have bits of broken metal floating around inside and through the oil, its going to ruin every other rotational part and bearing beyond repair. It can also lodge pieces in between the crownwheel and casing and crack your casing. Consider that gearbox totally ratshit and beyond repair with possibly very little salvagable parts left. Time to look for another complete gearbox and write that one off.
 
Is your VR4 an Aspec or a Jspec Carl?
If it's an Aspec you will have to change over one of your selectors on the box.
Yeah its a A-spec. Whats involved? I havn't pulled a box out or apart before to see the internals etc so its a bit foreign to me. Once I physically see one I will have more of a clue. Is it possible to fit a later model evo 1-3 box and transfer without too much hassle?
 
To fit an evo box and transfer you will need to source a 3.9 rear diff as well unless you want to use your transfer and change the final drive in the box.
Rob, read the first post again mate. It happened on launch not shifting. I'd guess on a messed up first gear throwing crap everywhere and lodging in and around the shift forks making getting out of first a pain.
But yes, when you sense a box has let go STOP! I broke both of my 1st gears at the track and stopped immediately and even then broken bits still get into everything!

And for the Aspec/Jspec swap you need to unbolt the shift lever that is vertical on the box. The other lever is fixed with a roll pin and you can't get it off without an air chisel!
Swap this and it will let you use you Aspec shifter cables.
 
Tim, there was method to my madness not just speculation :lol: . Here is how I come up with my theory ;)
Not knowing the full history of what happened moments before the launch I can only assume that there must have been a reason why 1/2 fork or fork rail end had fatigued or broken. Could have been cracked and decided to break off at that point in time when trying to shift to first gear??
Now picture this...
A broken 1/2 sihft fork or shift rail end would have made it seem like he selected 1st gear in the cabin... ie the gearknob can move to first gear in the cabin but the fork isnt physically moving the slider inside the box to engage first gear.
Then when he released the clutch, it made no noise, no jolt, no nothing. The gearbox would still be in neutral but his gearknob is sitting in first gear postion.
The broken fork or end, depending on how it is now positioned inside the box, would make it difficult to move the shift knob out of first gear position.
He also said that he cannot get any drive from first or second gears = the 1/2 hub sliders arent moving up/down to engage the gears. If teeth were broken he would have heard crunches of teeth not engaging properly by this time IMO
The 3/4 hub slider would still be working and he was able to reef it out of first and select 3rd gear to drive it most of the way home until one of those broken fork parts finds its way in between teeth between the 3rd intermediate and 3rd gear and the rest is history :lol:
1/2 = broken shiftfork or shit rail end
3rd = broken teeth on either 3rd intermediate or 3rd gear
With no 1,2,3 in the main cogbox working he is still able to select 5th gear which is secluded in the rear casing of the gearbox to get him home.
He has also stated there is no reverse now, which is a tricky buggar to say the least. As there is no reason for the teeth to be broken on the input shaft where the reverse idler gear drops to engage it, I can only assume that the top section of the shift rail end that moves up to drop the reverse idler arm down has broken off too.
He must have really yanked hard on the shift lever to get them in and out of gear to damage any of the rail ends :lol:
Thats my theory and it makes sense to me. Ive tried to look at it via few different possibilities but thats the only one that matches up to the story.
Like all things gearboxes though, unless its opened up we wont know for sure :)
 
gotta open it and share the pain with us all now.
evooox, sounds like a good theory, very well thought out.
third gear is right next to 1-2 selector fork as well. would be pretty easy for the selector to drop into 3rd and break stuff
may even be repairable for $4-500 in parts. maybe...
 
Good point Rob, I missed the bit about having to yank it out of 1st.
Could be an easy fix but I'd doubt it.
If it took out 3rd on both shafts then the cost of a new int shaft and 3rd gear won't be too cheap.
HEy Carl, let me know if you are going to bin the box. I might take it off your hands for spare parts depending on what is stuffed :D
 
Good point Rob, I missed the bit about having to yank it out of 1st.
Could be an easy fix but I'd doubt it.
If it took out 3rd on both shafts then the cost of a new int shaft and 3rd gear won't be too cheap.
HEy Carl, let me know if you are going to bin the box. I might take it off your hands for spare parts depending on what is stuffed :D
Got 2moro off work so will be removing box. Will put up photos for your enjoyment.......you sadistic bastards! Lol
 
Its just like opening up a Kinder Surprise.
You could get something really good to put a smile on your face, or you could end up getting fukd over with something totally lame like whatever the hell that shit's supposed to be in the picture below :lol:
"SURPRISE!!" :blink: Out of every egg you could have chosen off the shelf, YOU had to go and choose the most gayest one out the lot :lol:

hkegg1.jpg
 
Update. Car is up on stands and all intake pipes etc removed. Should have box out tomorrow after work. Also drained oil out and it has a nice amount of glitter in there lol. Iam now in the process of finding a new box from somwhere. I noticed the id code on the box says c51ph. Ive read this is the box with shit alloy selectors forks that break hmmmmm......Well what I would like to know is what gearbox exactly i should be looking for? This box by rights should be 3.5etc ratio yeah? In 5th at 100kph it sat at about 3500rpm. Can I grab any vr4 box with that ratio or is there more to consider? I ask because i can get a reconditioned one (not put in car) with the same ratio for a good price back home (nz) My new slotted rotors came in post today aswel ds 2500 on thier way too!;) This car was purchased as a cheap, rough, semi fast thrash wagon....this is starting to get out of hand :D
 

Latest posts

Back
Top